"It's a great test to see where we're at," he admitted, according to goal.com.
"It won't be the end story. Anyone can go to Manchester City and lose; they are such a strong outfit, so I won't be making huge judgements, win or lose."
Technically, Chelsea failed its test, losing 2-1 at the Etihad. But Lampard will take huge encouragement out of his team's performance.
Chelsea is clearly not yet capable of beating the best teams in the Premier League, having already been defeated at home by Liverpool this season, but it again showed that it can compete with England's elite.
The Blues have now lost five consecutive games against big-six opposition since Lampard took charge during the summer but during the opening quarter of the game in Manchester, it was Chelsea which looked like the side most capable of reeling in league leader Liverpool.
Chelsea had been slated for its performances on its last two trips to the Etihad. Antonio Conte's side suffered arguably the most one-sided 1-0 loss in Premier League history two seasons ago, while Maurizo Sarri's team was humiliated 6-0, the club's worst defeat in 28 years.
At that point, the gap between City and Chelsea looked as wide as it has ever been during the Roman Abramovich era.
However, Chelsea showed on Saturday that it is rapidly making up ground.
City was fortunate to level the game before the half-hour mark, with Kevin De Bruyne's low drive taking a decisive deflection off Kurt Zouma, though there was nothing lucky about Riyad Mahrez's solo strike eight minutes later.
Chelsea was unable to get itself back into the game as Pep Guardiola's side took control in the second half, but there were plenty of positives for the Blues, who restricted City to just 46.74 percent possession.
Tammy Abraham failed to get on the scoresheet but he looked right at home on such a grand stage, while youngsters Christian Pulisic, Fikayo Tomori and Reece James all impressed.
However, games at this level are decided by small details and Chelsea was ultimately punished for its sloppiness.
Jorginho gave the ball away in the lead-up to De Bruyne's equalizer, while Kepa Arrizabalaga was lucky to see Sergio Aguero strike the bar after giving the ball straight to the Argentine striker.
Emerson Palmieri, meanwhile, was clearly targeted by City and endured a torrid evening, meaning Lampard will have to ask himself if he erred in selecting the fullback.
Still, both he and his players will learn from this failed examination of their title credentials. This is a team that is clearly only going to improve and a top-four finish looks well within its reach.
"If you look at City," Lampard mused afterward, "they are an example to follow and we're only at the start of that process."
Chelsea, though, is progressing at a rate that nobody could have envisaged. When its next big test comes around, don't be surprised if it passes it.